PDX1 and neoplasm: In addition, since Lfng is co-expressed with Ptf1a during embryonic development, Pdx1-Cre-mediated Lfng deletion may cause defective differentiation and accumulation of pancreatic progenitor cells, which may accelerate tumor development due to an increase in tumor-initiating cells in the KrasG12D;Pdx1-Cre model.